A conventional Power Distribution Unit (PDU) is an assembly of electrical outlets (also called receptacles) that receive electrical power from a source and distribute the electrical power to one or more separate pieces of electronic equipment. Each such PDU assembly has a power input that receives power from a power source, and power outputs that may be used to provide power to one or more pieces of electronic equipment. PDUs are used in many applications and settings such as, for example, in or on electronic equipment racks. One or more PDUs are commonly located in an equipment rack (or other cabinet), and may be installed together with other devices connected to the PDU such as environmental monitors, temperature and humidity sensors, fuse modules, or communications modules that may be external to or contained within the PDU housing. A PDU that is mountable in an equipment rack or cabinet may sometimes be referred to as a Cabinet PDU, or “CDU” for short.
A common use of PDUs is supplying operating power for electrical equipment in computing facilities, such as data centers or server farms. Such computing facilities may include electronic equipment racks that comprise rectangular or box-shaped housings sometimes referred to as a cabinet or a rack and associated components for mounting equipment, associated communications cables, and associated power distribution cables. Electronic equipment may be mounted in such racks so that the various electronic devices (e.g., network switches, routers, servers and the like) are aligned vertically, one on top of the other, in the rack. One or more PDUs may be used to provide power to the electronic equipment. Multiple racks may be oriented side-by-side, with each containing numerous electronic components and having substantial quantities of associated component wiring located both within and outside of the area occupied by the racks.
As mentioned, many equipment racks may be located in a data center or server farm, each rack having one or more associated PDUs. Various different equipment racks may have different configurations, including different locations of and different densities of equipment within racks. As will be readily recognized, space within equipment racks is valuable with maximization of computing resources for any given volume being desirable.